The lawsuit by Dianna Waldridge, the widow of 60-year-old Parker Waldridge of Crescent, alleges negligence by Red Mountain Energy and Red Mountain Operating, both of Oklahoma City, and Patterson-UTI Drilling and Patterson-UTI Energy, both of Houston.

Patterson-UTI declined comment in a statement, saying it’s committed to preventing future such accidents. Red Mountain President Tony Say referred questions to his attorney, who did not immediately return a phone call for comment.